iOS gif图片保存到相册里面

通过路径转成data数据，写入本地相册就行了：

NSData *data = [NSData dataWithContentsOfFile:path];
        // 保存到本地相册
        ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
        [library writeImageDataToSavedPhotosAlbum:data metadata:nil completionBlock:^(NSURL *assetURL, NSError *error) {
            NSLog(@"Success at %@", [assetURL path] );
        }] ;